Car payment..co signer is now in bankruptcy!?

2.5 yrs ago i bought a brand new car dad cosigned since i was 18 at the time, now he is in bankruptcy and since 09/2007 i have not recieved a bill and when I call my car loan place i am directed to a national bankruptcy hotline. I have tried to pay my 300 a month that I have not missed once in those 2.5 years but am not allowed to. i tried calling hsbc early this year and asked to have my cosigner removed but was told it was immpossible and i would have to refinance on my own, however I do not make enough money for that as I am a student. So today I checked my credit with equifax and under negative accounts there is my car loan with 12,000 past due and under account status it says "charge-off'. I was wondering if anyone had any advice for me as I am very upset his bankruptcy is effecting my credit, also what does charge off mean? any help is welcome and thank u!